This invention relates to a low-frequency therapeutic device having a flexible adhesive sheet electrode (which is firmly adhered to the skin of a human body) which can stimulate nerves, activate muscular movement and promote blood circulation so as to ease various symptoms such as stiffness, pain paralysis, and fatigue by giving a low-frequency current having the same properties as those of a bioelectric current which flows inside the human body, to the inside of the human body by way of the skin.
Conventionally, there is known a low-frequency therapeutic device which is used in such a manner that a pair of electrodes are adhered onto the surface of the human skin and a high voltage pulse having a low frequency is applied between the electrodes so that an electric stimulus is given to the human body to apply a therapeutic effect.
This type of low-frequency therapeutic device comprises therapeutic elements which are adhered to the human body, and a controller for controlling the operation of therapeutic elements. These therapeutic elements and the controller, however, must be connected to each other by means of cords can and these cords bother a user of the device.
In view of the above, a low-frequency therapeutic device which is of a cordless type and is light-weight has been developed as described in Japanese Utility Model Laid-open No. HEI 3-5445, wherein the therapeutic device attaches adhesive conductors or electrodes to the bottom surface of a therapeutic main body incorporating a power source therein.
Although the therapeutic device described in the above publication has succeeded in making cords unnecessary and in acquiring light-weightedness, the size of the adhesive conductors are arranged corresponding to the size of the bottom surface of the therapeutic device. Accordingly, since the main body of the therapeutic device has an extremely poor flexibility, it is extremely difficult to adhere the adhesive conductors to the parts of the human skin which constantly move resulting in poor adhering of the adhesive conductors (for example, parts such as the shoulders or neck which vigorously move).
The smaller the main body of the therapeutic device becomes, the greater the above-mentioned problem. Furthermore, since the area of each adhesive conductor is small, the contact resistance between the adhesive conductor and the parts of the human skin increases, whereby a user feels a discomfort with pricking pains.
The above discomfort is brought to the user in a mechanism, wherein in the low-frequency therapy, in case a pair of electrodes which are made of adhesive conductors are placed on effective spots of the human body respectively, an electric current flows inside the human body so that a comfortable and effective therapy can be achieved, while in case a pair of electrodes are not placed on the effective spots respectively, when an output of electric pulse in generated, the electric current flows along the surface of the human skin without flowing inside the human body and give a discomfort to the user.
Furthermore, the conventional low-frequency therapeutic device is capable of operating in several modes such as tapping, massaging and vibrating upon varying the period of electric pulse generated. To obtain a desired mode or stimulus, however, the user must operate a mode selection switch each time he wants to change and obtain the desired mode, such an operation is cumbersome.
Furthermore, since the low-frequency therapeutic device is not provided with a case which can readily store the therapeutic device in a compact form, the carrying thereof is inconvenient.
Accordingly, it is an object of the present invention to provide a low-frequency therapeutic device which can overcome the above-mentioned defects.